SUPPLEMENTAL METHIONINE, CHOLINE, OR TAURINE AFFECT GALECTIN GENE EXPRESSION IN ADULT HOLSTEIN COW AND NEONATAL HOLSTEIN CALF NEUTROPHILS IN VITRO

Abstract

The aim of the study was to evaluate the effect of methyl donor supplementation on mRNA expression of galectin genes in cow and calf neutrophils in vitro. Galectins play a crucial role in homeostasis and disease regulation. Ten adult Holstein cows and five neonatal Holstein calves (3 wk. old) were used for isolation and in vitro culture of neutrophils. Neutrophils isolated from the adult cows were divided into two groups. Neutrophils from Group 1 were incubated with three concentrations of Lysine (Lys) to Met ratios of (3.6:1, 2.9:1, or 2.4:1). Neutrophils from Group 2 were also incubated with three concentrations of Lys to Met ratios and 50 μg /mL of LPS. Isolated neutrophils from calves were incubated with Met, Choline, and Taurine (37 °C, with 5% CO₂ or 4 hours). Met did not affect LGALS expression in Group 1 cows.

In Group 2, however, relative mRNA expression of LGALS9 was higher in neutrophils treated with 3.6 Lys: Met and 2.9 Lys: Met concentrations compared to 2.4 Lys: Met (0.33, 0.36 and 0.16 respectively) (P<0.05).  A Met X LPS interaction was also observed in regard to the expression of LGALS8. LGALS8 transcription decreased when neutrophils were treated with LPS at 3.6 Lys: Met (No LPS=0.89 LPS= 0.56) (P<0.05). On the contrary, LGALS8 expression increased at 2.9 Lys: Met in the presence of LPS (No LPS=0.52 LPS= 1.95)(P<0.05). Treatment with LPS alone increased the expression of LGALS4 (P<0.05) and tended to increase LGALS12 (P<0.10) compared to control.

In calves, LGALS-2, -7, and -9 were undetected. LGALS-1, -3, - 4, -8, and -12 were all reduced in neutrophils treated with 2.4 and 2.6 Lys: Met compared to 3.6 Lys: Met. Increasing Choline concentration tended to reduce LGALS1 (P<0.05) but reduced LGALS8 (P<0.05). Increasing taurine reduced LGALS1 and tended to reduce LGALS12. These results shed light on the modulation of galectin expression in cow and calf neutrophils in response to methyl donors.